Which of the statements given below are true for the structure of water molecule ?
(i) Oxygen undergoes `sp^(3)` hybridisation.
(ii) Due to presence of two lone pairs of electrons on oxygen the H - O - H bond angle is `118.4^(@)`.
(iii) Due to angular geometry the net dipole moment of water is not zero, `mu = 1.84 D`.

Options

A. (i) and (ii)
B. (ii) and (iii)
C. (i) and (iii)
D. only (ii)

Explanation

To determine which statements about the structure of the water molecule (H₂O) are true, we will analyze each statement one by one.

### Step 1: Analyze Statement (i)
**Statement (i):** Oxygen undergoes `sp^(3)` hybridization.

- In a water molecule, the oxygen atom is bonded to two hydrogen atoms and has two lone pairs of electrons. This results in a total of four electron pairs around the oxygen atom.
- The hybridization of oxygen in this case is indeed `sp^(3)` because it involves the mixing of one s orbital and three p orbitals to form four equivalent hybrid orbitals.

**Conclusion:** Statement (i) is **true**.

### Step 2: Analyze Statement (ii)
**Statement (ii):** Due to the presence of two lone pairs of electrons on oxygen, the H-O-H bond angle is `118.4°`.

- In water, the presence of two lone pairs of electrons on the oxygen atom does affect the bond angle. The ideal bond angle for `sp^(3)` hybridization is `109.5°`, but the repulsion from the lone pairs compresses the bond angle.
- The actual H-O-H bond angle in water is approximately `104.25°`, not `118.4°`.

**Conclusion:** Statement (ii) is **false**.

### Step 3: Analyze Statement (iii)
**Statement (iii):** Due to angular geometry, the net dipole moment of water is not zero, `μ = 1.84 D`.

- Water has a bent or angular geometry due to the two lone pairs on the oxygen atom, which creates an uneven distribution of charge.
- This results in a net dipole moment that is not zero. The dipole moment of water is indeed approximately `1.84 D`, indicating that the molecule is polar.

**Conclusion:** Statement (iii) is **true**.

### Final Conclusion
Based on the analysis:
- Statement (i) is true.
- Statement (ii) is false.
- Statement (iii) is true.

Thus, the true statements regarding the structure of the water molecule are (i) and (iii).

### Answer:
The correct answer is that statements (i) and (iii) are true.

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